The proposed research involves the study of the contribution of pragmatic (world) knowledge to the comprehension of sentences by brain damaged patients. This approach recognizes certain limitations of the formal linguistic approach and attempts to provide a richer understanding of human communication by focusing on the pragmatic processes utilized by speakers and listeners in everyday discourse. Through the linguistic devices of anaphora, ellipsis, indirect speech acts, and implicature, we plan to examine the relation between brain damage and pragmatic processing. We hope to isolate the nature of pragmatic disorders as involving either accessing pragmatic knowledge or using pragmatic knowledge as a basis for implicature. We also hope to be able to determine whether pragmatic implicature and logical inferential capacities can be dissociated on the basis of brain damage. We feel that these studies will further elucidate the nature of communication disorders due to brain damage and will, at the same time, suggest new insights into the mechanisms through which world knowledge is integrated with linguistic information in language comprehension.